Fix a typo in sampled_function.cc

Thanks to Pablo Speciale for reporting this.

Change-Id: Icd526856f91dba98f7abf86b098b210a89556445

examples/sampled_function.cc

@@ -68,7 +68,7 @@ int main(int argc, char** argv) {
   // Evaluate the function f(x) = (x - 4.5)^2;
   const int kNumSamples = 10;
   double values[kNumSamples];
-  for (int i = 0; i < 10; ++i) {
+  for (int i = 0; i < kNumSamples; ++i) {
     values[i] = (i - 4.5) * (i - 4.5);
   }
 
@@ -84,5 +84,6 @@ int main(int argc, char** argv) {
   Solver::Summary summary;
   Solve(options, &problem, &summary);
   std::cout << summary.BriefReport() << "\n";
+  std::cout << "Expected x: 4.5. Actual x : " << x << std::endl;
   return 0;
 }